carp84 commented on a change in pull request #9501: [FLINK-12697] [State Backends] Support on-disk state storage for spill-able heap backend URL: https://github.com/apache/flink/pull/9501#discussion_r328473311
########## File path: flink-state-backends/flink-statebackend-heap-spillable/src/main/java/org/apache/flink/runtime/state/heap/space/Allocator.java ########## @@ -0,0 +1,50 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.flink.runtime.state.heap.space; + +import java.io.Closeable; + +/** + * Implementations are responsible for allocate space. + */ +public interface Allocator extends Closeable { + + /** + * Allocate space with the given size. + * + * @param size size of space to allocate. + * @return address of the allocated space, or -1 when allocation is failed. + */ + long allocate(int size); Review comment: We will check against `-1`, see `SkipListUtils.NIL_VALUE_POINTER`. We don't throw exception here because the definition of methods in `StateMap` don't throw exceptions, so we will need to handle the exception somewhere if we throw any in lower level functions, then no big difference from handling `-1`. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
